U.S. Patent Application Publication No. 2013/0213027 (Bird et al.) discloses a one-way brake for a torque converter stator. The stator disclosed is formed with blades spaced mutually angularly about an axis. The stator disclosed further includes a hub located radially inward of the blades. The stator includes an outer race which includes pockets spaced angularly about the axis. Each pocket includes a rocker, sometimes called a strut, and a spring, which continually urges a respective rocker to pivot in its pocket toward engagement with cams formed on an outer surface of the inner race, arranged radially inward of the hub. The one-way rocker brake prevents counterclockwise rotation of the stator relative to the stator shaft and race.
U.S. Patent Application Publication No. 2014/0197002 (Lindemann et al.) discloses a symmetrical strut for a rocker one-way clutch that provides the same functionality whether installed with a top or a bottom side into a pocket for a race for the clutch.
A common problem with rocker one-way clutches is that the spring arranged between the housing and the strut can move out of place because the position of the spring is not maintained. Typical rocker one-way clutch 50 is shown in FIG. 2. Strut 51 is rotatably mounted within a pocket of housing 52 and spring 54 is wedged in groove 55. Spring 54 is simultaneously contacting strut 51. Spring 54 can slip along the surface of strut 51 along directions d1 and d2 shown in FIG. 3. If spring 54 of such a rocker one-way clutch slips and/or becomes jammed, then the torque converter fails to perform the multiplication function properly. Additionally, if spring 54 breaks, total replacement is necessary.
Another problem with rocker one-way clutches having an asymmetrical strut is that the strut can be unintentionally incorrectly assembled. Typical rocker one-way clutch 50 shown in FIG. 2 includes improperly installed strut 56 which has caused spring 58 to become dislodged from groove 59 of housing 52. In this improper arrangement, the contact angle between strut 56 and ramp 60 of inner race 61 is incorrect. Additionally, due to this improper arrangement, spring 58 can slip and/or become dislodged or jammed between strut 56 and housing 52. During operation of the rocker one-way clutch in the free-wheel mode, strut 56 can crush spring 58 as strut 56 is urged clockwise. A damaged spring can cause failure of one-way clutch 50 because a crushed spring can cause the inner and outer races to be non-rotatably locked.
FIG. 4a shows a perspective view of strut 51 which broadly includes main body 62, first neck portion 63a and second neck portion 63b. Main body 62 is arranged to engage with and be restrained by a pocket of housing 52 shown in FIGS. 2 and 3. First and second neck portions 63a and 63b are arranged to lock the inner and outer races of the one-way clutch. Strut 51 has top surface 64. When strut is properly installed in a one-way clutch, top surface 64 is facing upward and second neck portion 63b is facing radially outward. FIG. 4b shows a perspective view of strut 51 with bottom surface 65 facing upward. When bottom surface 65 is facing upward, strut 51 can be improperly assembled in a stator assembly. First neck portion 63a is substantially planar on all surfaces even on the surface arranged to contact a spring.
Thus, there has been a long-felt need for a strut having a cutout to maintain the position of a spring and a mechanism for ensuring the strut is properly assembled within the stator.